//Returns true if the provided function parameter 'func' returns true for all elements in a set, 
//Otherwise, it returns false
function all( arr, func = Boolean ) {
  return arr.every( func );
}
console.log( 'all([4, 2, 3], num => num > 1): ', all( [ 4, 2, 3 ], num => num > 1 ) );
console.log( 'all([1, 2, 3]): ', all( [ 1, 2, 3 ] ) );
/*
all([4, 2, 3], num => num > 1):  true
all([1, 2, 3]):  true
*/
